If you’re new to working out — or new to working out with the goal of getting faster, going longer or just improving — you probably haven’t started monitoring heart rate yet. Sure, you might know how far you’re running, but do you know how hard? Training with heart rate zones can help you track your intensity, which will help you get to that next level of fitness.

Monitoring Heart Rate Zones

The best way to figure out your exact heart rate in each zone isn’t a formula, says Sally Edwards, a former pro marathoner and Ironman triathlete who has written 24 books on the subject of heart rate. As a starting point, she recommends finding your max heart rate with the formula of 220 minus your age, but she adds that this isn’t always 100% accurate.

Edwards believes that it takes data collection before you can really set your five heart rate zones: hard, high-moderate, low-moderate, high-easy and easy (otherwise known as Zones 1–5). Hard, of course, is the one you’ll spend the least amount of time in, while high-easy and easy are the heart rate zones you’ll use for most of your base miles.

Most people tend to run in the low to high-moderate zones but completely miss the hard and the easy zones — and that’s what Edwards, who owns a company called Heart Zones, is hoping to change. The best training regimens combine truly easy recovery after bursts of intense effort, but they rarely linger in the moderate zone.

Find an App and Use the Data

Tracking heart rate is just the first step in heart rate training. The next step is to take the data and measure it, either solo or with a coach. By keeping track of your heart rate zones per workout, you can measure whether a training plan is actually effective. Use an app like UA Record that tracks workouts in real time and stores past workouts.

In reviewing your data, look for trends:

Your speed should be increasing in all of the zones as you continue to train.

For example, you could run a 10-minute mile in July at 140 beats per minute, but in September, your pace was down to 9 minutes per mile at 140 BPM.

You should also be able to stay in a zone longer if endurance is your goal.

For example, in July, you could run in the hard-easy zone for 30 minutes before your heart rate started to rise, but in September, you ran for 43 minutes.

The Monitor Matters

Your monitor should feel unobtrusive, like it’s part of you. Fitness trackers with heart rate monitors on the wrist aren’t as accurate during exercise, so do your research before buying one. If your monitor’s chest strap is itching, too tight or uncomfortable, find a new one.

Know Your Goals

It might seem obvious, but how you train depends on what your goals are. Monitoring your heart rate helps keep your intensity in check. If you’re a seasoned runner aiming to race for a PR in a 5K, you’ll focus on short workouts in the hard or high-moderate zones. If you’re training for your first marathon, you’ll stay in the easy and high-easy zones as you increase volume. In terms of running long when you haven’t before, it’s best to increase intensity or volume, but not both at once or else you risk injury.

Don’t Stress Out About Burning Fat

Every zone burns fat, Edwards says. As long as you’re working out, you’re torching calories. Focus on sticking to your planned workout and having a solid, protein-packed recovery meal that’s low on processed carbs. You’ll see the best fat-burning results by watching your diet, not by chugging along in Zone 2 for hours only to eat donuts afterwards.

Train More in Zones 1 and 5, and Less in Zone 3

As mentioned earlier, the most efficient way to build speed and endurance is to vary intensity. First, spend time going slow and easy; this will train your body to be efficient and not burn through your glycogen stores. Then spend time going fast and hard, so your muscles begin to grow and adapt to high speeds. That gray/moderate zone doesn’t offer as many gains, but if it’s the pace you enjoy, then allow yourself to train there occasionally. As long as you’re still getting those quality workouts, you’re doing great.

Data-Driven Doesn’t Mean Soulless

You probably got into working out and running to get in shape or to prep for a race, but most of us end up finding a certain amount of joy from the practice. Don’t let constant monitoring change that for you. Be aware of your heart rate, but also be aware of your heart itself. Hold onto that love of working out, and if you find logging data into a software program is taking away from that — and you don’t have major goals or races ahead — consider taking a break. Chances are, you’ll likely miss the feedback loop and will be strapping on your heart rate monitor again.